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The Science of Homosexuality: What is Known?Many Christians are content with the nineteenth century "disease model" of homosexuality (usually equating it to an addiction like alcoholism). Following a disease model, homosexuality carries the added burden of immorality (often portrayed as a Christian "crisis of faith"), and this only adds to the fervent efforts by many to find a "cure." What is clear over the course of the last one hundred years of research and review is that gay men and lesbian women keep appearing within society and that a "cure" has not been readily found (nor is one necessary).
The debate within medical and scientific communities became more discerning as it was repeatedly noticed that homosexuals compared to heterosexuals were not necessarily predisposed to mental illness nor could they be accurately identified by researchers through "blind" interviews (an investigator interviewing a subject and unaware of the subject's sexual orientation cannot reliably predict the sexual orientation afterwards).37 This led the health care community to re-examine the nineteenth century "disease model" assumption. For instance, while the pathology, disability, and impairment of cancer is obvious, that of homosexuality is not obvious--except for the social prejudice and bigotry gay men and lesbian women face from society. In the past 25 years, the American Psychological Association, the American Psychiatric Association, and the American Medical Association have changed their definition of homosexuality to that of a "normal variant" (like being left handed) rather than as a "disease."38-40 That is to say, for some human beings, a homosexual orientation is their "natural" state of being. Why has this consensus developed among a diverse group of scientists, health care professionals, and some clergy? Scientific research over the past five decades has given people more information about sexual orientation than any previous generation, but we are still far from an adequate understanding. Those critical of the theory that biological factors direct homosexual orientation (especially those believing that homosexuality is a conscious willful choice) often mention that these biological associations have never been proven or shown to cause homosexuality. By analogy, cigarette smoking is very strongly associated with the development of lung cancer, but it has never been proven or shown to cause lung cancer by strict scientific criteria. A biological role in determining sexual orientation is furthered challenged by an appreciation of the many complex variables which combine to impact human sexuality. However, evidence pointing to a biological basis for homosexuality is reasonable, sound, and should not be ignored.In studies of twin siblings, researchers have noted significant suggestions of a genetic link to homosexuality.41-49 Yet, such genetic linkages are often questioned because they lack absolute predictive value. Why is this? It is because complex human traits are often forged and influenced by a variety of factors including an interplay between so-called matters of "nature and nurture." A review of left-handedness provides a useful illustration of "nature and nurture" dynamics. Many left-handed people (nature) were forced to use their right-hand by well-meaning parents and instructors (nurture). The number of naturally occurring left-handed individuals (as a predictably occurring "natural variant") has been modified by environmental nurturing (parents and teachers preferring right-handedness). Such modification (which thwarts absolute sensitivity or specificity of a genetic linkage to a particular human trait) should not invalidate results, but should serve as a reminder of the complex nature of human beings. Natural variants (such as eye color, hand preference, skin pigmentation) may represent a difference from the majority and may be considered "atypical" or "unconventional," but this difference is morally neutral and should not be maligned as "abnormal," "unnatural," or "perverse."In 1993, studies of male siblings with maternal gay relatives (studies of females are in progress), identified an X-linked (region Xq28) chromosomal association (concordance) in homosexuals.50 The evidence from this study supports a genetic contribution to homosexuality as an X-linked trait inherited from maternal genes. While this small study has not been replicated outside the National Institutes of Health and should be taken as tentative, the study withstood critical independent scientific peer review prior to publication.51 A recent study by Canadian researchers failed to identify the same chromosomal association, although there were some significant differences in the sampling techniques and methods confounding clear cross-comparisons.52 There will likely be more ambiguity in genetic research studies as time goes on because it is still difficult to classify/define one as heterosexual, homosexual or bisexual without simply asking the research subject. And given the varying degrees of social stigma regarding such self-identification, research will remain very challenging.In addition, anatomical brain studies suggest a physical difference between brain structures in homosexual and heterosexual identified men, particularly in the hypothalamus (although cause versus effect is unclear).53,54 Furthermore, there is evidence suggesting a concomitant role of the prenatal hormone levels (estrogens and androgens) and their concentration ratios as a factor (although not causal) in sexual orientation development.55 Many of these studies are being independently confirmed and future developments are certain to aid in our fledgling scientific understanding.
Homosexuality exists in nearly every species of observed mammals and is in all likelihood irreversibly established in humans at a very early age (probably by age five).56 How genetics and environmental factors work together in forging homosexual orientation is unclear, but a genuine homosexual orientation is not a conscious choice. Furthermore, as a phenomena, homosexual orientation is the natural state of being for a minority of human individuals. There is no evidence to suggest that homosexual orientation is caused by a history of childhood molestation or sexual trauma. Sadly, both homosexual and heterosexual individuals are at equal risk (and rate) for such tragic events.57 In addition, research has not supported the contention that upbringing "creates" a homosexual person. Homosexual and heterosexual (also known as "straight" in common idiom) people come from similar family situations. Research on families has consistently invalidated the once popular notion that "castrating mothers" or "detached and/or hostile fathers" are both necessary and sufficient causes of homosexuality.58 For Adventist Christian parents with gay/lesbian children, the self-blame heaped upon parenting and parenting strategies is unwarranted--nor should gay/lesbian offspring be viewed as a curse.
47. RC Pillard, JD Weinrich. "Evidence of familial nature of male homosexuality" in Archives of General Psychiatry 1986; 43: 808-12, cited by RC Friedman, JI Downey, in the New England Journal of Medicine 1994; 14: 923-930.
48. M King, E McDonald. “Homosexuals who are twins: a study of 46 probands" in the British Journal of Psychiatry 1992; 160: 407-9, cited by RC Friedman, JI Downey, in the New England Journal of Medicine 1994; 14: 923-930. 49. ED Eckert, TJ Bouchard, J Bohlen, LL Heston. "Homosexuality in monozygotic twins reared apart" in the British Journal of Psychiatry 1986; 148: 421-5, cited by RC Friedman, JI Downey, in the New England Journal of Medicine 1994; 14: 923-930. 52. George Rice, C Anderson, N Risch and G Ebbers. “Male homosexuality: absence of linkage to microsatellite markers at Xq28,” in Science, 284 (1999), 665-7. 53. DF Swaab, MA Hofman. "An enlarged suprachiasmatic nucleus in homosexual men" in Brain Research 1990; 537: 141-8, cited by RC Friedman, JI Downey, in the New England Journal of Medicine 1994; 14: 923-930. 54. Simon Levay. "A difference in hypothalamic structure between heterosexual and homosexual men." Science 1991; 253: 1034-7. 55. HFL Meyer-Bahlberg. "Psychobiologic research on homosexuality" in Child-Adolescent Psychiatric Clinics of North America 1993; 2: 489-500, cited by RC Friedman, JI Downey, in the New England Journal of Medicine 1994; 14: 923-930. 56. HI Kaplan and BJ Sadock, editors. "Homosexuality and Homosexual Behavior" by WJ Gadpaille in the Comprehensive Textbook of Psychiatry--6th edition. Baltimore: Williams and Wilkins, 1995, 1323-26. 57. Margaret Schneider, J Glassgold, L Brown. “Implementing the Resolution on Appropriate Therapeutic Responses to Sexual Orientation: A Guide for the Perplexed,” in Professional Psychology: Research and Practice, Vol 33 (2002), No 3, 265-276. 58. RC Friedman. Male Homosexuality: A Contemporary Psychoanalytic Perspective. New Haven (Connecticut): Yale University Press, 1988. |
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